Rancilio Rocky Upper Doser Star This is the upper portion only of the Rocky's three-part doser star assembly, it sweeps grounds through the top of the doser chamber as the lever is pulled. COMPATIBILITY Fits: Rancilio Rocky (doser model) Works with: the doser's lower star and center shaft (sold separately) to form the complete three-piece assembly INSTALLATION In-housing swap, requires opening the doser to access the star assembly. PRO TIPS Since this is only one of three doser star components, inspect the lower star and shaft for wear at the same time, replacing just the upper piece on a worn assembly often leaves inconsistent dosing between chambers.